Mr W pesters me regularly for this & once you've tried it you will understand why!
The steak needs to be thin so if you are buying from a supermarket you will need to slice it in half, if you buy it from a butcher he can do it for you.
Serves 4 Approx £1.41 per person
Prep time 10 mins Cooking time 20 mins
450g rump steak, sliced into strips
1 onion, sliced
4 sub rolls
2 tbsp mayonaisse
2 tsp mustard (I used Dijon)
50g grated cheese
Toss the strips of steak in some salt & pepper to season.
Split the rolls & mix the mayo & mustard together. Spread the mustard mayo onto the cut sides of the rolls.
In a large frying pan heat 1 tbsp of oil & 1 tbsp of butter over a low-medium heat.
Add the onions & cook for about 10 minutes until golden & slightly caramelised.
Set aside & keep them warm.
Turn the heat up to med-high & cook the steak for about 5 mins or to your liking.
Heat the grill.
Fill the rolls first with the steak then top with the onions. Sprinkle over some grated cheese & place under the grill until melted & gooey!